Syringe for sequential delivery of different fluids

ABSTRACT

A syringe for sequentially administering different fluids includes a floating piston which separates the syringe into a first portion for receiving a first fluid to be administered and a second portion for receiving a second fluid to be administered. The floating piston includes a fluid tight seal which initially separates the first and second portions of the syringe and a piercing needle which penetrates the fluid tight seal to connect the second portion of the syringe to the syringe needle after the first fluid has been discharged from the syringe.

TECHNICAL FIELD

[0001] This invention relates generally to the sequential administrationof different fluids, for example, the administration of a medicationfollowed immediately by the administration of a normal saline solution,and more particularly to an improved syringe design which assurescomplete delivery of the first fluid followed immediately by completedelivery of the second fluid.

BACKGROUND AND SUMMARY OF THE INVENTION

[0002] Various medical procedures require the sequential administrationof different fluids. For example, administration of the cardiac drugknown as Adenosine must be followed immediately by the administration ofa normal saline solution in order to get the drug into circulationrapidly. Heretofore the sequential administration of different fluidshas been accomplished utilizing two syringes, one loaded with the firstfluid to be administered and the other loaded with the second fluid tobe administered. The two needle system is not only awkward but alsoincreases the risk that medical personnel will suffer inadvertentneedlesticks.

[0003] A previous attempt to solve the foregoing problem is shown anddescribed in published U.S. patent application US 2002-0035351-A1.Referring to FIG. 1 of the present application, the device disclosed inthe published application comprises a single barrel double chambersyringe 10 having a barrel 1 and a plunger 2 which is utilized in theconventional manner to force fluids contained within the barrel 1outwardly through a hollow needle 8. This is accomplished by means of apush stopper 3 secured to the plunger 2 and made of a pliable materialto maintain a fluid tight seal around its outer periphery. A hollowfloating plunger 5 situated within the barrel 1 is likewise comprised ofa pliable material to maintain a fluid tight seal around its outerperiphery. The floating plunger 5 divides the barrel 1 into a firstcompartment 4 and a second compartment 6.

[0004] The hollow needle 8 is secured in a hub 9 situated at theopposite end of the barrel 1 from the plunger 2. The hollow needle 8comprises a first component extending outwardly from the barrel 1 andthe hub 9 and a piercing component extending from the hub 9 into thesecond chamber 6 of the barrel 1. The hollow needle 8 is provided with aporthole 7 to assure full delivery of fluid contained within the secondchamber 6.

[0005] In the operation of the syringe 10 a first fluid is loaded intothe second chamber 6 and a second fluid is loaded into the first chamber4. As the push stopper 3 is forced downwardly (FIG. 1) into the barrel 1under the action of the plunger 2 the fluid within the first chamber 4and the floating plunger 5 function to force the first fluid outwardlyfrom the second chamber 6 through the hollow needle 8. As the floatingplunger 5 moves downwardly it eventually engages the piercing componentof the hollow needle 8 which begins to penetrate the floating chamber 5.Meanwhile, the remainder of the first fluid is forced out of the secondchamber 6 through the porthole 7 and the hollow needle 8.

[0006] Continued downward movement of the push stopper 3 under theaction of a plunger 2 causes the piercing component of the hollow needle8 to fully pierce the floating plunger 5 thereby allowing the secondfluid to flow outwardly from the first chamber 4 through the hollowneedle 8. Movement of the push stopper 3 toward the hollow needle 8under the action of the plunger 2 continues until all of the secondfluid has been discharged from the syringe 10 through the hollow needle8.

[0007] While eliminating the problems inherent in sequentiallyadministering two different fluids utilizing two syringes, the deviceshown and described in published application US-2002-0035351-A1 involvesdifferent problems. First, the hollow needle through which the differentfluids are sequentially administered must be provided with a porthole.As will be appreciated by those skilled in the art, forming a portholein a hollow needle of the type utilized in medical syringes involvesdifficult and expensive manufacturing steps. Second, the axialdimensions of the hollow needle utilized in the device disclosed in thepublished application must be very accurately controlled. Thus, if thepiercing component of the needle is too short the floating plunger willnot be properly penetrated thereby preventing proper administration ofthe second fluid. Conversely, if the piercing component of the hollowneedle is too long complete delivery of the first fluid cannot beassured.

[0008] The present invention comprises an improved syringe design whichovercomes the foregoing and other problems that have long sincecharacterized the prior art. In accordance with the broader aspects ofthe invention an otherwise conventional syringe is provided with afloating piston comprising upper and lower portions. The lower portionmay comprise a spongy material encased in a flexible shell and having apiercing needle mounted therein. Alternatively, the lower portion maycomprise a flexible shell filled with a suitable gas such as air. Theupper portion comprises a seal formed from a non-coring elastomericmaterial.

[0009] In the practice of the invention a first fluid to be administeredis loaded into the barrel of the syringe below the floating piston. Asecond fluid to be delivered is loaded into the barrel of the syringeabove the floating piston. As the plunger of the syringe is moved intothe barrel the first fluid is forced outwardly through the needle of thesyringe under the action of the second fluid and the floating piston.The floating piston eventually engages the discharge end of the barrelthereby forcing the entirety of the first fluid outwardly through theneedle. Continued movement of the plunger of the syringe causes thepenetrating needle of the floating piston to penetrate the sealcomprising the upper portion of the floating piston. At this point thesecond fluid is connected in fluid communication with the syringe needlethrough the penetrating needle of the floating piston. Further inwardmovement of the plunger of the syringe forces all of the second fluidoutwardly through the penetrating needle of the floating piston and thesyringe needle.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] A more complete understanding of the invention may be had byreference to the following Detailed Description when taken inconjunction with the accompanying Drawings, wherein:

[0011]FIG. 1 is a longitudinal sectional view of a prior art singlebarrel double chamber syringe;

[0012]FIG. 2 is a longitudinal sectional view of the syringe of thepresent invention showing the syringe in a first stage of its operation;

[0013]FIG. 3 is an enlargement of a portion of FIG. 2;

[0014]FIG. 4 is a view similar to FIG. 2 showing the syringe at a laterstage in its operation;

[0015]FIG. 5 is a view similar to FIG. 2 showing a syringe of thepresent invention at a still later stage in its operation; and

[0016]FIG. 6 is an illustration similar to FIG. 2 showing a syringe ofthe present invention at the completion of its operation.

DETAILED DESCRIPTION

[0017] Referring now to the Drawings, and particularly to FIG. 2thereof, there is shown a syringe 20 incorporating the presentinvention. In many respects the syringe 20 is conventional inconstruction and operation. Thus, the syringe 20 includes a barrel 22which receives fluid to be administered. A hollow needle 24 is securedto one end of the barrel 22 by a hub 26 and is coupled in fluidcommunication with the interior of the barrel 22. The end of the barrel22 remote from the needle 24 may be provided with a radially extendingflange 28 which is typically engaged by the fingers of an individualoperating the syringe 20.

[0018] The syringe 20 further includes a plunger 30 adapted for axialmovement within the barrel 22. The plunger 30 extends to a piston 32which forms a fluid tight seal with the interior surface of the barrel22. The end of the plunger 30 remote from the piston 32 may be providedwith a plate 34 which is typically engaged by the thumb of an individualoperating the syringe 20.

[0019] Referring to FIGS. 2 and 3, the syringe 20 differs fromconventional syringes in that it is provided with a floating piston 40.The floating piston 40 includes a lower portion 42 and an upper portion44.

[0020] Referring particularly to FIG. 3, the lower portion 42 of thefloating piston 40 comprises a body 46 formed from a resilient materialwhich may be spongy in nature. The body 46 is surrounded by a flexiblelayer 48 formed from a material approved for medical applications, forexample, silicone. Alternatively, the lower portion 42 may comprise aflexible shell filled with a suitable gas such as air. The lower portion42 of the floating piston 40 further comprises a piercing needle 50. Thepiercing needle 50 is mounted and supported by the body 46 of the lowerportion 42 of the floating piston 40.

[0021] The piercing needle 50 is hollow throughout its length and ispreferably either equal to or greater in diameter than the needle 24 ofthe syringe 20. The piercing needle 50 may be provided with an enlargedportion at the end thereof facing the needle 24 of the syringe 20 inorder assure fluid communication between the piercing needle 50 and thesyringe needle 24.

[0022] The upper portion 44 of the floating piston 40 comprises anon-coring elastomeric material. In use, the upper portion 44 forms afluid tight seal with the interior surface of the barrel 22 of thesyringe 20. As will be appreciated by those skilled in the art, thefunction of the upper portion 42 of the floating piston 40 is to dividebarrel 22 of the syringe 20 into upper and lower chambers and toinitially maintain a fluid-tight barrier therebetween.

[0023] Operation of the syringe 20 of the present invention isillustrated in FIGS. 2, 4, 5, and 6. Referring first to FIG. 2, a firstfluid to be administered is loaded into the portion of the barrel 22 ofthe syringe 20 situated below the floating piston 40. A second fluid tobe administered immediately following completion of the delivery of thefirst fluid is loaded into the portion of the barrel 22 of the syringe20 situated above the floating piston 40. The floating piston 40, andparticularly the upper portion 42 thereof, comprises a fluid tight sealwhich maintains separation between the two fluids.

[0024] Referring next to FIG. 4, administration of the first fluid isaccomplished by moving the plunger 30 inwardly, that is, from theposition illustrated in FIG. 2 toward the position illustrated in FIG.4. As the plunger 30 is moved inwardly, the floating piston 40 and thesecond fluid positioned within the barrel 22 of the syringe 20 betweeenthe floating piston 40 and the plunger 30 function to force the firstfluid out of the barrel 22 through the syringe needle 24. FIG. 4illustrates the floating piston 40 bottomed out in the barrel 22 of thesyringe 20 with all of the first fluid having been delivered through thesyringe needle 24.

[0025] Referring next to FIG. 5, further inward movement of the piston30 compresses the resilient material 46 and/or the gas comprising thelower portion 42 of the floating piston 40 thereby causing the piercingneedle 50 to penetrate the upper portion 44 of the floating piston 40.In this manner the second fluid to be administered, which is situatedbetween the floating piston 40 and the plunger 30, is connected in fluidcommunication with the syringe needle 24 through the hollow interior ofthe piercing needle 50. Further inward movement of the plunger 30 forcesthe second fluid to be administered out of the barrel 22 of the syringe20 through the piercing needle 50 and the syringe needle 24. This actioncontinues until the piston 32 of the plunger 30 bottoms out asillustrated in FIG. 6. At this point the syringe 20 is typicallydisposed of in accordance with approved syringe disposal techniques.

[0026] It will therefore be understood that the present inventioncomprises a syringe for sequentially administering different fluidswhich overcomes the problems that have characterized the prior art. Inparticular, manufacture of the syringe of the present invention involvesthe addition of a unique floating piston to an otherwise conventionalsyringe. Manufacture of the components parts of the syringe of thepresent invention does not involve complicated and expensivemanufacturing techniques, nor does it involve precise control over thedimensions of the component parts of the device.

[0027] Although preferred embodiments of the invention have beenillustrated in the accompanying Drawings and described in the foregoingDetailed Description, it will be understood that the invention is notlimited to the embodiments disclosed, but is capable of numerousrearrangements, modifications, and substitutions of parts and elementswithout departing from the spirit of the invention.

1. A syringe for sequentially administering different fluids comprising:a syringe body having a hollow interior for receiving the fluids to beadministered; a syringe needle mounted at one end of the syringe bodyfor administering the fluids therefrom; a plunger mounted within theinterior of the syringe body for movement therein toward the end of thesyringe body comprising the syringe needle to force fluids outwardlyfrom the interior of the syringe body through the syringe needle; theplunger further comprising a piston forming a fluid tight seal with theinterior of the syringe body; a floating piston slidably supportedwithin the hollow interior of the syringe body and forming a fluid tightseal with the syringe body which divides the syringe body into a firstportion for receiving the first fluid to be administered and a secondportion for receiving the second fluid to be administered; and thefloating piston further comprising means for connecting the second fluidto be administered in fluid communication with the syringe needle afterall of the first fluid to be administered has been dischargedtherethrough.
 2. The syringe according to claim 1 wherein the floatingpiston is further characterized by an upper portion forming a fluidtight seal with the interior of the syringe body, a lower portioncomprising resilient means, and a piercing needle mounted in andsupported by the resilient lower portion and having a hollow interior.3. The syringe according to claim 2 wherein the resilient means of thelower portion comprises a spongy material.
 4. The syringe according toclaim 2 wherein the resilient means of the lower portion comprises agas.
 5. The syringe according to claim 2 wherein the first portion ofthe floating piston comprises a non-coring elastomeric material.
 6. Thesyringe according to claim 2 wherein the lower portion of the floatingpiston comprises a spongy material having the piercing needle mountedtherein and a resilient coating surrounding the spongy material.
 7. Thesyringe according to claim 1 wherein the syringe needle is characterizedby a predetermined diameter, and wherein the piercing needle of thefloating piston is characterized by a diameter equal to or greater thanthe diameter of the syringe needle.
 8. For use in conjunction with asyringe of the type comprising a syringe body having a hollow interior,a hollow syringe needle mounted at one end of the syringe body andcoupled in fluid communication with the interior thereof, and a plungermounted for movement within the syringe body toward the syringe needleto force fluids contained within the syringe body outwardly through thesyringe needle, the plunger further comprising a piston forming a fluidtight seal with the interior of the syringe body, a floating pistonadapting the syringe for the sequential administration of differentfluids comprising: means forming a fluid tight seal with the interior ofthe syringe body which divides the syringe body into a first portion forreceiving a first fluid to be administered and a second portion forreceiving a second fluid to be administered; and means for connectingthe second portion of the syringe body in fluid communication with thesyringe needle after the first fluid to be administered has beendischarged from the syringe body through the syringe needle under theaction of the plunger.
 9. The syringe according to claim 6 wherein thefloating piston is further characterized by an upper portion forming afluid tight seal with the interior of the syringe body, a lower portioncomprising resilient means, and a piercing needle mounted in andsupported by the resilient lower portion and having a hollow interior.10. The syringe according to claim 9 wherein the resilient means of thelower portion comprises a spongy material.
 11. The syringe according toclaim 9 wherein the resilient means of the lower portion comprises agas.
 12. The syringe according to claim 9 wherein the first portion ofthe floating piston comprises a non-coring elastomeric material.
 13. Thesyringe according to claim 9 wherein the lower portion of the floatingpiston comprises a spongy material having the piercing needle mountedtherein and a resilient coating surrounding the spongy material.
 14. Thesyringe according to claim 8 wherein the syringe needle is characterizedby a predetermined diameter, and wherein the piercing needle of thefloating piston is characterized by a diameter equal to or greater thanthe diameter of the syringe needle.
 15. For use in conjunction with asyringe of the type having a cylindrical barrel, a floating pistonincluding a fluid tight seal which initially separates first and secondportions of the syringe barrel and a piercing needle which penetratesthe fluid tight seal to connect the first and second portions of thesyringe barrel in fluid communication.